1. Field of the Invention
This invention relates to failover in a polling adapter and more particularly relates to failover in a polling adapter without support from an application server.
2. Description of the Related Art
An enterprise information system (EIS) is generally any kind of computing system that offers high quality of service that is capable of supporting some large organization while dealing with large volumes of data. EISs provide a technology platform that enables organizations to integrate and coordinate their business processes. They provide a single system that is central to the organization and ensures that information can be shared across all functional levels and management hierarchies. EISs are invaluable in eliminating the problem of information fragmentation caused by multiple information systems in an organization, by creating a standard data structure. EISs provide the information infrastructure for an enterprise such that users can expect to have fluid access to all business functions an enterprise can offer regardless of which system hosts those services and functions.
Typically, application servers or integration servers are used to access a shared EIS through an adapter. Adapters provide a mechanism that allows for the integration of existing EIS infrastructure and process integration applications. Generally, there are two types of adapters which include application adapters and technology adapters. Application adapters are designed to interface with a specific application programmable interface (API) for a specific version of an EIS. These may include adapters for SAP, Siebel, PeopleSoft, Oracle, and IBM applications. Technology adapters are designed to support a standard technology interface to any EIS that supports the same interface such as adapters for a database, file system, or web service.
In a clustered environment, multiple redundant adapters may need to access the same EIS system at the same time. Adapters typically access an EIS by polling an event table stored on the EIS. In some cases, when an adapter is processing inbound communication via polling, there is only one event table that contains the publishable information, so only one adapter can access that information at a time. If more than one adapter were attempting to operate on the same event table as may be the case when using redundant polling adapters for failover protection, competition for events would occur, resulting in invalid data being sent to the client. Conventional application servers often do not support the notion of a ‘singleton’ adapter to allow automatic failover. Therefore, there is a need not currently resolved in the art to allow a polling adapter to fail over to a new instance of a polling adapter even when the application server doesn't support this.